<template>
    <div class="todo-footer" v-show="getLength">
        <label>
            <input type="checkbox" :checked="isAll" @change="checkAll"/>
        </label>
        <span>
          <span>已完成{{doneTotal}}</span> / 全部{{getLength}}
        </span>
        <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
    </div>
</template>

<script>
    export default {
        name: 'MyFooter',
        props: ['todos', 'checkAllTodo', 'clearAllTodo'],
        computed: {
            doneTotal() {
                const x = this.todos.reduce((pre, current) => {
                    return pre + (current.done ? 1 : 0)
                }, 0);
                return x;
            },
            getLength() {
                return this.todos.length
            },
            isAll() {
                return this.doneTotal === this.getLength
            }
        },
        methods: {
            checkAll(e) {
                this.checkAllTodo(e.target.checked)
            },
            clearAll() {
                if (confirm('确定删除吗？')) {

                    this.clearAllTodo()
                }
            }
        }


    }
</script>

<style scoped>
    /*footer*/
    .todo-footer {
        height: 40px;
        line-height: 40px;
        padding-left: 6px;
        margin-top: 5px;
    }

    .todo-footer label {
        display: inline-block;
        margin-right: 20px;
        cursor: pointer;
    }

    .todo-footer label input {
        position: relative;
        top: -1px;
        vertical-align: middle;
        margin-right: 5px;
    }

    .todo-footer button {
        float: right;
        margin-top: 5px;
    }
</style>
